This invention relates to a crankcase ventilator for an internal combustion engine, having a liquid separator in communication with the crankcase via a vent line and in communication with the vacuum line of the engine.
It is known to draw off the oil vapor from the crankcase of an internal combustion engine, and to filter it and cool it, in order to recover the oil.
German Patent document DE-AS 12 68 902 describes a known crankcase ventilator for internal combustion engines. From a vent opening on the crankcase a connecting duct leads upward to a vacuum connection. A condensate settling chamber with a filter mesh is disposed in the connecting duct, and a drain tube with a shut-off valve leads into the open air. The separated oil flows directly along the wall of the vent connection, back into the crankcase. However, in the event of a fairly high gas velocity in the ventilating connection the oil is prevented from flowing back. It is carried along by the gas stream into the vacuum connection and enters into the combustion process.
Furthermore, German Patent document DE-OS 31 07 191 provides a drain line in the interior of the ventilation duct, through which the liquid is carried from the collecting chamber into the crankcase. This drain tube, however, is reliable in operation only if the collecting chamber is in an exact horizontal position, such that the liquid is evenly distributed around the collecting chamber. In internal combustion engines for motor vehicles equipped with such crankcase ventilation, however, the horizontal position is not always maintained. Therefore a fairly large amount of liquid can accumulate in the collecting chamber and cannot be reliably returned to the crankcase. This liquid is entrained in the case of a comparatively high gas velocity and thus can enter the combustion process.